1. Field of the Invention
The present invention relates to improvement of a ball mount apparatus and a mount method for mounting solder balls, solder bumps, or the like, on a work such as a substrate, a frame, or the like, and particularly relates to a ball mount apparatus and a mount method which are improved in inspection of surplus balls or an error in ball sucking, and balls left due to a mounting error after mounting balls.
The present application is based on Japanese Patent Application No. Hei. 11-220729, which is incorporated herein by reference.
2. Description of the Related Art
In the background art, there is known a ball mount apparatus having a ball supply portion and a work positioning portion (a position where solder balls are mounted on a work) and reciprocating between these portions so as to mount solder balls on a positioned work. In such a ball mount apparatus, a ball inspection unit is provided for making inspection as to whether there is an error in ball sucking or not, while a mount head moves relatively between the ball supply portion and the work positioning portion.
In such a ball mount apparatus, generally, the longitudinal direction of a work is regarded as an X-axis, and the relative moving direction of the mount head from a ball suction position to a ball mount position is regarded as a Y-axis. This is because the dimension of a mount head along the relative moving axis (Y-axis) is reduced so as to miniaturize the ball mount apparatus. Further, a ball inspection unit has a light emission portion and a light reception portion disposed in a direction perpendicular to a relative moving course of the mount head, that is, in the longitudinal direction of the work. Thus, the ball inspection unit is disposed on the relative moving course (on Y-axis) of the mount head.
The ball inspection unit makes the mount head move over a laser sensor relatively, so that the light reception portion receives laser light projected from the light emission portion to thereby detect surplus balls, an error in sucking balls, and residual balls.
Recently, however, with the increase of the area of a work to which balls are mounted in a lump, the distance between the light emission portion and the light reception portion in the inspection unit is increased. Thus, the inspection accuracy is lowered due to diffusion of light. Further, with the miniaturization of balls, the inspection accuracy is required to be too high for the background art to cope with.
It is an object of the present invention to provide a ball mount apparatus and a mount method in which, in order to solve the foregoing problems, a ball inspection unit makes inspection in the lateral direction of a work so that the distance between a light emission portion and a light reception portion in the ball inspection unit is reduced, whereby the inspection accuracy is prevented from lowering, and increasing in size of the unit can be avoided.
In order to attain the foregoing object, the present invention provides a ball mount apparatus which comprises: a work conveying path provided in a longitudinal direction of a work on which balls are to be mounted; a ball supply tray for supplying balls, the ball supply tray being disposed so that a longitudinal direction thereof substantially coincides with that of the work; a mount head disposed so that a longitudinal direction thereof substantially coincides with that of the work; and a ball inspection unit for inspecting ball-suction by the mount head, the ball inspection unit being disposed so that a projecting direction of inspection light from the ball inspection unit intersects the longitudinal directions substantially perpendicularly; and further provides a mount method using the ball mount apparatus.